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Nutrient enrichment and interspecific competition modulate growth performance of invasive plant species regardless of nematodes
No full textInvasions by non-native plant species are thought to be facilitated by factors like escape from specialized natural enemies and increased resource availability. However, the success of invasive plants also depends on interactions with native plants and soil organisms, including nematodes. Plants can experience both beneficial and harmful interactions with nematodes. Yet, research on how nematodes and nutrient levels interact to affect competition between invasive and native plants is lacking. We conducted a multi-species greenhouse experiment involving 10 invasive species and 20 native species to test the separate and combined effects of nutrient levels and nematodes on performance of individual invasive plant species, as well as their competition with native plant communities. High-nutrient conditions significantly enhanced the aboveground biomass (+119.4%), height (+26.9%), reproduction (+21.0%) and proportional aboveground biomass (+21.2%) of invasive plant species. Conversely, competition from native plant communities significantly reduced the mean aboveground biomass, height, and reproduction of the invasive species by 55.3%, 20.3% and 13.5%, respectively. For invasive plants grown without competition, the high-nutrient treatment significantly enhanced total biomass and root diameter, although it decreased the root mass fraction, independent of nematode presence. In addition, in the absence of competition, nematodes increased the specific root length of invasive plants by 3.6% under low-nutrient conditions but reduced it by 10.1% under high-nutrient conditions. These results indicate that nutrient enrichment, competition and biotic interactions with nematodes can all play critical roles in shaping the growth and adaptive strategies of invasive plant species.publishe
Effort and time costs influence motivational asymmetries in self-benefitting vs pro-environmental decisions
No full textMitigating climate change requires individuals to adopt more pro-environmental behaviours, many of which come at a personal cost. Costs such as the time and effort associated with certain behaviours are integral to everyday decision-making and can significantly shape people’s motivation to act. In this preregistered study, we employed an experimental paradigm designed to quantify how people discount effort (measured via a grip-force device) and time (operationalised as waiting time) for self-benefitting and pro-environmental outcomes. Participants (n = 74) could earn monetary rewards for themselves (in half of the trials) and for reducing carbon emissions (in the other half). We observed a higher willingness to incur time and effort costs for self-benefitting than for pro-environmental outcomes, in particular when the rewards offered were higher. Moreover, computational modelling revealed rewards were discounted nonlinearly by both time and effort: effort discounting was best described by a parabolic function, and temporal discounting by a hyperbolic function. Finally, when linking experimental behaviour to self-report measures, we found that participants who were more motivated to invest time and effort for the environment also reported greater willingness to support costly climate change mitigation policies, whereas climate change beliefs were not significantly associated with the cost-incurring task behaviour. Our approach highlights differences in how individuals respond to costs associated with personal vs environmental benefits and presents a promising tool for further research on environmental decision-making.publishe
The nascent polypeptide-associated complex (NAC) as regulatory hub on ribosomes
No full textThe correct synthesis of new proteins is essential for maintaining a functional proteome and cell viability. This process is tightly regulated, with ribosomes and associated protein biogenesis factors ensuring proper protein production, modification, and targeting. In eukaryotes, the conserved nascent polypeptide-associated complex (NAC) plays a central role in coordinating early protein processing by regulating the ribosome access of multiple protein biogenesis factors. NAC recruits modifying enzymes to the ribosomal exit site to process the N-terminus of nascent proteins and directs secretory proteins into the SRP-mediated targeting pathway. In this review we will focus on these pathways, which are critical for proper protein production, and summarize recent advances in understanding the cotranslational functions and mechanisms of NAC in higher eukaryotes.publishe
Four Perspectives on the Link Between Polarization and Online Media : A Literature Review
No full textDer Artikel stellt Theorien zum Zusammenhang von gesellschaftlicher Polarisierung und Online-Medien seit den 2000er-Jahren vor. Er nutzt dafür etwa 85 systematisch gesammelte Beiträge, vorwiegend aus der amerikanischen Politik- und Kommunikationswissenschaft, aus den Computational Social Sciences und ihren Vorläufern sowie teilweise aus der Sozialpsychologie und Wirtschaftswissenschaft. Es werden vier Theorieperspektiven und Fragestellungen hervorgehoben, die die Problematisierung des Zusammenhangs von Online-Medien und Polarisierung in den analysierten Arbeiten durchziehen: 1) ideologische Polarisierung und die Exposition mit politisch einseitigen Nachrichten oder kontroversen Diskussionen; 2) interaktionale Polarisierung und „cross-cutting networks“; 3) affektive Polarisierung im Angesicht von Online-Inzivilität; 4) wahrgenommene Polarisierung und exemplarische Gruppenzugehörigkeit.publishe
Germany’s Energy and Climate Policy as an Ecology of Games
No full textThis article analyses a key shift in German energy and climate policy. Following the Fukushima disaster in Japan, the German government decided to shut down eight old nuclear reactors in the short term, and to phase-out the remaining reactors within the next seven years. At the same time, its ambitious climate policy goals relied on energy security through a growing share of renewable energies, an expanded energy grid, improved energy efficiency, and technological innovations, as well as the use of natural gas as a so-called “bridging technology.” In this context, this article provides an overview of competing explanations circulating in the political and social science literature for this path-breaking policy shift, and demonstrates how network analysis can be used to offer an alternative explanation — one in which this policy shift was decisively shaped by both the structural context and situational dynamics.publishe
Long-term research presence mitigates hunting pressure and shapes mammal communities in the Congo Basin
No full textOverhunting in tropical African forests threatens wild mammal populations and consequently the livelihoods of local communities dependent on wild meat. Long-term research sites can help mitigate hunting pressure and support wildlife, yet their influence on mammal communities remains understudied. Since 2002, the LuiKotale Bonobo Project has operated in the buffer zone of Salonga National Park, Africa's largest protected forest area. The study site spans approximately 500 km2, including areas reserved for research activities, and areas where hunting has taken place until recently. Using camera trapping data collected between June 2022 and August 2023, we assessed mammalian (1) diversity, (2) occupancy, (3) relative abundance and (4) community composition, in hunted vs. research areas. Species richness was higher in the research area (36 vs. 33 mammal species detected), while overall diversity was higher in the hunted forest. However, ungulates were 53 % more abundant in the research area, while rodent detections were 137 % higher in hunted zones, suggesting a shift in functional composition associated to subsistence hunting. Occupancy patterns revealed a non-linear association with distance from research camps and a linear, negative association with the number of human signs, with the highest occupancy probabilities predicted at intermediate distances and in areas of lower human disturbance. These findings highlight the influential role long-term research sites play in shaping mammal communities and emphasize the need for conservation strategies that effectively balance biodiversity preservation with local access to resources.publishe
Reduced parental brood visit rate in wild zebra finches <i>Taeniopygia castanotis</i> is correlated with high maximum daily ambient temperature
No full textAs a result of a warming global climate, understanding how organisms adjust their behaviour to environmental thermal conditions has become an increasingly important question in animal biology. Temperature‐driven adjustments in parental care are potentially important given the repercussions on offspring size, quality and survival. In 2015 and 2016 we monitored parental care for 83 zebra finch Taeniopygia castanotis breeding attempts in the wild with known brood sizes. We recorded the frequency of parental visits to the nest together with mean maximum ambient temperature experienced between day 7 and 14 of the nestling period. We found that for each increase of 1°C in the daytime temperature there was a 0.91% reduction in the hourly rate of parental visits, whilst also accounting for other variables such as nestling age, time of season, and wind speed. Our data suggest that nestlings may receive less food under thermally challenging conditions, which is consistent with recent studies that demonstrate offspring are smaller when reared during periods of high temperature. Understanding the behavioural drivers that may contribute to the production of smaller offspring in extreme heat conditions could prove useful to forecast long‐term consequences for fitness triggered by climate change.publishe
Exoplanetary Exploration and the End of the World in 22 Minutes : Philosofiction in Outer Wilds
No full textIn this essay, we work over the imageries of exoplanetary exploration in digital games, observing their connections with concepts from media theories and science fiction studies. This articulation aims to comprehend how, in a philosofictional manner, games fictionally extrapolate the conditions of possibility for astronomical observation, allegorizing a series of contemporary themes regarding the technoscientific knowledge of space and planetary systems. As an analytical procedure, we observe game assets, images, and design dynamics, articulating them theoretically in three axes: technoscientific paraphernalia, compared planetology, and oblique orbits. With this, we understand how games can creatively approach (and, in the light of science fiction, extrapolate) contemporary relationships between science, technology, and society.publishe
Conformation and binding of 12 Microcystin (MC) congeners to PPP1 using molecular dynamics simulations : a potential approach in support of an improved MC risk assessment
No full textMicrocystins (MCs) occur frequently during cyanobacterial blooms worldwide, representing a group of currently about 300 known MC congeners, which are structurally highly similar. Human exposure to MCs via contaminated water, food or dietary supplements can lead to severe intoxications with ensuing high morbidity and in some cases mortality. Currently, one MC congener (MC-LR) is almost exclusively considered for risk assessment (RA) by the WHO. Many MC congeners co-occur during bloom events, of which MC-LR is not the most toxic. Indeed, MC congeners differ dramatically in their inherent toxicity, consequently raising question about the reliability of the WHO RA and the derived guidance values. Molecular dynamics (MD) simulation can aid in understanding differences in toxicity, as experimental validation for all known MC congeners is not feasible. Therefore, we present MD simulations of a total of twelve MC congeners, of which eight MC congeners were simulated for the first time. We show that depending on their structure and toxicity class, MCs adapt to different backbone conformations. These backbone conformations are specific to certain MC congeners and can change or shift to other conformations upon binding to PPP1, affecting the stability of the binding. Analysis of the interactions with PPP1 demonstrated that there are frequently occurring patterns for individual MC congeners, and that published PPP interactions could be reproduced. In addition, common but also unique patterns were found for individual MC congeners, suggesting differences in binding behaviour. The MD simulations presented here therefore enhance our understanding of MC congener-specific differences and demonstrated that congener-specific investigations are prerequisite for allowing characterisation of yet untested or even unknown MC congeners, thereby allowing for a novel potential approach in support of an improved RA of microcystins in humans.publishe
